package com.stock_t.utils;

import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

/**
 * 客户端工具类
 * 
 * @author ruoyi
 */
public class ServletUtils
{
    /**
     * 获取String参数
     */
    public static String getParameter(String name)
    {
        return getRequest().getParameter(name);
    }

    /**
     * 获取String参数
     */
    public static String getParameter(String name, String defaultValue)
    {
        return convert(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取Integer参数
     */
    public static Integer getParameterToInt(String name)
    {
        return convert(getRequest().getParameter(name), 0);
    }

    /**
     * 获取Integer参数
     */
    public static Integer getParameterToInt(String name, Integer defaultValue)
    {
        return convert(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取Boolean参数
     */
    public static Boolean getParameterToBool(String name)
    {
        return convert(getRequest().getParameter(name), false);
    }

    /**
     * 获取Boolean参数
     */
    public static Boolean getParameterToBool(String name, Boolean defaultValue)
    {
        return convert(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取request
     */
    public static HttpServletRequest getRequest()
    {
        return getRequestAttributes().getRequest();
    }

    /**
     * 获取response
     */
    public static HttpServletResponse getResponse()
    {
        return getRequestAttributes().getResponse();
    }

    /**
     * 获取session
     */
    public static HttpSession getSession()
    {
        return getRequest().getSession();
    }

    public static ServletRequestAttributes getRequestAttributes()
    {
        RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
        return (ServletRequestAttributes) attributes;
    }

    /**
     * 将字符串渲染到客户端
     * 
     * @param response 渲染对象
     * @param string 待渲染的字符串
     * @return null
     */
    public static String renderString(HttpServletResponse response, String string)
    {
        try
        {
            response.setStatus(200);
            response.setContentType("application/json");
            response.setCharacterEncoding("utf-8");
            response.getWriter().print(string);
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 是否是Ajax异步请求
     * 
     * @param request
     */
    public static boolean isAjaxRequest(HttpServletRequest request)
    {
        String accept = request.getHeader("accept");
        if (accept != null && accept.indexOf("application/json") != -1)
        {
            return true;
        }

        String xRequestedWith = request.getHeader("X-Requested-With");
        if (xRequestedWith != null && xRequestedWith.indexOf("XMLHttpRequest") != -1)
        {
            return true;
        }

        String uri = request.getRequestURI();
        if (StringUtils.inStringIgnoreCase(uri, ".json", ".xml"))
        {
            return true;
        }

        String ajax = request.getParameter("__ajax");
        if (StringUtils.inStringIgnoreCase(ajax, "json", "xml"))
        {
            return true;
        }
        return false;
    }

    /**
     * 将字符串转换为指定类型
     * 
     * @param <T> 泛型
     * @param value 值
     * @param defaultValue 默认值
     * @return 结果
     */
    public static <T> T convert(Object value, T defaultValue)
    {
        if (value == null)
        {
            return defaultValue;
        }
        if (value instanceof String && StringUtils.isEmpty(String.valueOf(value)))
        {
            return defaultValue;
        }
        try
        {
            if (defaultValue instanceof Integer)
            {
                return (T) Integer.valueOf(String.valueOf(value));
            }
            else if (defaultValue instanceof Long)
            {
                return (T) Long.valueOf(String.valueOf(value));
            }
            else if (defaultValue instanceof Double)
            {
                return (T) Double.valueOf(String.valueOf(value));
            }
            else if (defaultValue instanceof Float)
            {
                return (T) Float.valueOf(String.valueOf(value));
            }
            else if (defaultValue instanceof Boolean)
            {
                String valueStr = String.valueOf(value);
                return (T) Boolean.valueOf(valueStr);
            }
            else
            {
                return (T) value;
            }
        }
        catch (Exception e)
        {
            return defaultValue;
        }
    }
}
